Nonwoven structure for reinforcing resinous material

ABSTRACT

A nonwoven structure and apparatus and method for masking it where the structure includes successive strips of linear material extending in overlapping relation across it and where the end of each of the strips at one side of the structure is laterally offset in the same direction with respect to the end of each of the strips at the opposite side.

R. E. SMITH .Sept. 25, 1973 NONWOVEN STRUCTURE FOR'RI-JINFORCINGRESINOUS MA I ERlAIJ 5 Sheets-Sheet 1 Original Filed April 5, 1969 mm Mmm Q 5 INVENTOR. A ay 5 jlzmw WYQLMW A TTORN E Y5 NONWOVEN STRUCTUREFOR" REINFORCING RESINOUS MATERIAL Original Filed April 5, 1969 E. SMITH5 Sheets-Sheet z III :m WK

INVENTOR For 5 SM/7H vBY wyg

ATTORNEYS Sept. 25, 1973 R, sM|TH 3,761,345

NONWOVEN STRUCTURE FOR REINFORCING HRSTNOUS MATERIAIJ Original FiledApril 3, 1969' 5 Sheets-Sheet is .Z/ 6W; .9 .95;; 2g; 3

INVENTOR.

For f. JM/fi/ BY ATTORNEYS I 25, 1973 R. E.VSMITH 3,761,345

NONWOVEN STRUCTURE FOR REINFORCING RESINOUS MATERIAL Original FiledApril 5, 1969 v 5 Sheets-Sheet 4 Flg. INVENTOR.

Aoy jM/m BY ATTORNEYS 25, 1973 R. E. SMITH 3,761,345

NONWOVEN STRUCTURE FOR REINFORCING RESINOUS MATERIAL Original FiledApril 5, 1969 5 Sheets-Sheet 5 3,761,345 NONWOVEN STRUCTURE FORREINFORCING RESINOUS MATERIAL Roy E. Smith, 1721 Fallbrook Road, Toledo,Ohio 43614 Continuation of abandoned application Ser. No. 813,218, Apr.3, 1969. This application Apr. 16, 1971, Ser.

Int. Cl. B3211 /12 U.S. Cl. 161-57 14 Claims ABSTRACT OF THE DISCLOSUREA nonwoven structure and method and apparatus for producing it of whichthe following is a specification and this application is a continuationof US. application Ser. No. 813,218, filed Apr. 3, 1969 and nowabandoned.

BACKGROUND OF THE INVENTION Heretofore, both conventional bonded orglued together nonwoven mats of either continuous linear material orshort lengths of linear material such as glass yarns or strands havebeen subject to severe limitations. While nonwoven mats or structures ofchopped or short lengths of linear material provide excellentmultidirectional reinforcement for articles made of plastics and thelike, the structures are difiicult to fabricate within manufacturingspecifications. Uncontrolled deviations from manufacturingspecifications result in mats possessing nonuniform strengthcharacteristics between different production runs and even havingstrength variations within the same mat from the same production run.Variation in mat thickness is one example of nonuniformity ofmanufacture that gives rise to mat strength variations. For example, abonded mat of chopped glass strands or yarns may vary from manufacturingspecifications as much as plus or minus 20% or more, e.g. mat thickness.Further, because manufacturing processes employ resinous glues such aspolyesters to bond the linear material together into a coherent body,nonwoven structures or mats of bonded together short strands or yarnsare stiff and therefore lack conformability. Also, the resinous gluebecomes a barrier to resin absorption by the mat in subsequentoperations where the mat is a reinforcement for plastic articles.

While mats of continuous multifilament linear material such as glassstrands or glass yarns are manufactured with better control, resultingnonwoven structures or mats do not given the multidirectional strengthof the bonded mat of chopped or short lengths and also tend to be toostiff, e.g. poor conformability. Conventional manufacturing apparatustends to direct the continuous multifilament linear material onto amoving surface such as a moving conveyor in substantially transversedisposition with respect to the movement of the conveyor surface. Thusresulting nonwoven structure or mat does not provide uniform strength inall directions, although the strength of the mat or an articlereinforced by the mat or structure may be greater in the direction ofthe strand lay than a nonwoven structure of chopped or discontinuouslinear material. Moreover, because such processes employ resinous gluesuch as polyesters to bond or adhere the linear material together into acoherent structure, the structures are rigid and do not easily conformin molds. Also, the glue is a barrier to resin absorption by the mat insubsequent operations where the mat is a reinforcement for plasticarticles.

I "United States Patent 0 3,76l,345 Patented Sept. 25, 1973 ice Anobject of the invention is an improved reinforcement structure and amethod and apparatus for producing it that overcomes limitations of theprior art.

Another object of the invention is an improved and more uniformlyconstructed nonwoven reinforcement structure of linear material havingimproved multidirectional strength characteristics.

Still another object of the invention is a nonwoven multilayerreinforcement of linear material having improved conformability andbetter resin absorption characteristics.

Yet another object of the invention is to provide reinforced articles ofimproved strength.

Other objects and advantages of the invention will become apparent asthe invention is hereinafter described in more detail with referencemade to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat simplified viewin elevation of a multistation apparatus for manufacturing an improvednonwoven structure of linear material according to the principles of theinvention.

FIG. 2 is a plan view of the apparatus shown in FIG. 1.

FIG. 3 is a portion of a layer of a multilayer nonwoven structure oflinear material according to the principles of the invention.

FIG. 4 is a more complete showing of the layer of the nonwoven structureillustrated in FIG. 3.

FIG. 5 is a three layer nonwoven structure of linear material accordingto the principles of the invention employing the layer shown in FIGS. 3and 4 and produced using the apparatus shown in FIGS. 1 and 2.

FIG. 6 is another three layer nonwoven structure of linear materialaccording to the principles of the invention.

FIG. 7 is a plan view of a modified second station for the multistationapparatus shown in FIGS. 1 and 2 for producing yet another multilayernonwoven structure according to the principles of the invention.

FIG. 8 is a view in elevation of the modified second station shown inFIG. 7.

FIG. 9 is a portion of the multilayer nonwoven structure produced usingthe multistation apparatus of FIGS. 1 and 2 modified to employ thesecond station shown in FIGS. 7 and 8.

FIG. 10 shows still another modified nonwoven reinforcement structure oflinear material according to the principles of the invention.

FIG. 11 is a view in perspective of another second station for use withthe multistation apparatus shown in FIGS. 1 and 2 where apparatussupplies chopped or short linear material for a layer to produce thestructure of FIG. 10.

FIG. 12 shows yet another nonwoven reinforcement structure according tothe principles of the invention.

FIG. 13 is a somewhat simplified view in elevation of apparatus forproducing the nonwoven structure illustrated in FIG. 12.

FIG. 14 shows a four layer nonwoven structure according to theprinciples of the invention.

FIG. 15 is a somewhat simplified view in elevation of apparatus forproducing the four layer nonwoven structure illustrated in FIG. 14.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show apparatusfor producing a multilayer reinforcement structure according to theprinciples of the invention using continuous multifilament linearmaterial such as continuous filament glass strands.

While it is preferred to use linear material including bundles ofcontinuous filaments such as continuous filament glass strands, otherlinear material such as monofilaments may be employed. Further, theinvention may use twisted linear material such as continuous filamentglass yarn, cord, etc. Moreover, linear material other than glass suchas nylon, polyester, and the like may be employed. Also, one may employlinear material of discontinuous or staple filaments, either twisted oruntwisted. It may be at times be advantageous to use texturedmultifilament linear material such as bulky yarn. The use of glass toexplain the invention is by way of example only.

While it is not necessary, it is generally preferred to use continuousfilament glass strands having a larger number of filaments, e.g. 1600 to2000 or more filaments; however, linear material having a fewer numberof filaments, such as 200 to 800 or more, may be effectively employedand in certain applications may be preferred.

The apparatus shown in FIGS. 1 and 2 includes a strand conveyingarrangement such as a tenter providing moving endless tenter belts orchains 11 and 12 that advance by suitable motor and drive means andstrand handling apparatus for locating glass strand in predeterminedfashion at spaced apart zones to produce reinforcement structure 13 ofthree layers.

FIGS. 1 and 2 illustrate apparatus for producing the nonwovenreinforcement structure 13 and includes three stations for locatingglass strands in predetermined relationship on the tenter 10, onestation for each layer of the multilayer nonwoven reinforcementstructure 13. The first station 14 includes means for positioning agroup or plurality of glass strands into a first or bottom layer ofsuccessive strips extending in predetermined overlapping relationrunning obliquely across the width of the tenter 10 with the glassstrands in closely spaced usually touching mutually parallelrelationship running lengthwise of the strips. The second station 16positions a second layer in intimate association on the first layer andincludes glass strands extending in closely spaced usually touchingmutually parallel relationship lengthwise of the tenter 10. The thirdstation 18 locates a plurality of glass strands in intimate associationon the second layer and includes successive strips extending inpredetermined overlapping relation running obliquely across the width ofthe tenter 10 with the glass strands in closely spaced usually touchingmutually parallel relationship running lengthwise of the strips.

The first station 14 includes means for traversing a band adjacentmutually parallel glass strands in predetermined relationship to anadvancing zone between the moving chains 11 and 12 of the tenter 10,such band folding back and forth across the width of the advancingchains 11 and 12 in overlapping relation to form a bottom or first layer20. The traversing means includes a carriage unit 21, which has a frame23 and a carriage 24.

As shown, the frame 23 is a longitudinal box-like unit located above andextending obliquely across the width of the tenter 10 at a predeterminedangle to the tenters center line. The frame 23 holds the carriage 24 inspaced relation above the tenter chains 11 and 12.

The carriage 24 includes a longitudinal guide support 26 extendingwidthwise of the frame 23 and, in a row, a plurality of side-by-sideguide tubes 27 positioned along the length of the support 26. Suitablemotor and drive means reciprocates the carriage 24 lengthwise of theframe 23, such reciprocation being oblique to the tenter 10. FIGS. 1 and2 show the support 26 located horizontally and the guide tubes 27, whichpierce the support 26 to open on its upper surface, disposed verticallyand depending on the support 26 to terminate just above the planecontaining the upper horizontal paths of the chains 11 and 12.

A suitable source such as a creel 29 provides a plurality of continuousfilament glass strands 30 to the carriage unit 24. As illustrated inFIGS. 1 and 2 the strands 30 advance as a band 31 from the creel 29,which is located in spaced relation from the tenter 10 and carriage unit24. The strands 30 travel individually through the guide tubes 27.

The speed of the advancing endless chains 11 and 12 and the traversingspeed of the carriage 24 on the frame 23 are in proportion to orient theband 31 of glass strands 30 in fixed relation across the chains. Theband 31 forms successive strips 32 extending obliquely in foldedoverlapping relation across the tenter 10 (the reinforcement structure13). These strips 32 form two groups of alternate strips where each ofthe groups extends from one side of the layer 20 to the opposite sidetoward a third side, viz. an end. Each of the two groups of stripsextend at different angles. The disposition of the strips places the endof each of the strips at one side of the layer 20 laterally offset inthe same direction with respect to the end of each of the strips at theopposite side. The strands 30 run lengthwise within each of the strips32 to extend at the same predetermined angle to the center line of thetenter 10 (also to the center line of the layer 20) as the strips 32.

Suitable means on the chains 11 and 12 engage or grab each of thestrands 30 to hold them in fixed predetermined relation as the carriage24 traverses the strands 30 across the advancing zone between thechains. The FIGS. 1 and 2 illustrate pins or hooks 33 on the chains 11and 12. As the carriage 24 reciprocates, the guide tubes 27 positioneach of the strands 30, at the end of each traversing stroke, in frontof an advancing hook 33, which engages each of the properly locatedstrands 30 to capture the strand and move the strand forward with it. Asthe carriage 24 moves to orient a succeeding portion of the band 31 as astrip 32 across the width of the tenter 10, the individual strands 30are drawn somewhat taut.

From FIGS. 3 through 5 it can be seen that the band 31 of glass strands30 runs back and forth obliquely across the width of the tenter 10 inoverlapping relation to form the strips 32 comprising the bottom layer20. FIGS. 3 and 4 more clearly illustrate the folded and overlappingdisposition of the strips 32 that continues throughout the layer 20where an initial strip portion 40 extends obliquely across the width ofthe tenter 10' (between the hooks 33 on the endless chains 11 and 12).The initial strip portion 40 has a leading edge 40', a trailing edge 40"and a plurality of closely associated or adjacent mutually parallelglass strands 30 extending lengthwise therein. The strip 40 forms anangle A with the center line of the layer 20 and the tenter 10. As thecarriage 24 traverses the band 31 of strands 30 obliquely across thetenter 10 to lay the initial strip portion 40 between the chains 11 and12, each strand 30 turns or is captured on an associated hook '33 andpulled somewhat taut. The carriage 24 moves the strands 30 togetherobliquely back across the Width of the tenter 10 to form a second stripportion 42 with a leading edge 42' and a trailing edge 42". In relationto the initial strip portion 40 the strip 42 is located such that itsleading edge 42' converges on the trailing edge 40. While the ends ofthe strips 32 may terminate on the chains 11 and 12 in substantiallyadjacent side-by-side relationship or registry, the adjacent corners ofthe strip ends may be touching or in overlapping relation.

The leading edge 42, trailing edge 42", and all glass strands 30 withinthe strip portion of 42 form an angle B with the center line of thetenter 10, the longitudinal layer 20 and the structure 13. As shown, theangle B is larger than an angle A. The frame 23 is rotatably mounted topermit changes in angles A and B. While angle A can vary, it is normallyin the range of from 30 to degrees. The magnitude of the angle A dependsupon the needs of the structure 13. The angle B also varies, itsmagnitude depending on such things as the width of the band 31 anddistance between the chains -11 and 12 of the tenter 10.

The third strip portion 43 of the band 31 overlaps the second stripportion 42 and is disposed exactly like the initial strip portion 40,e.g. makes an angle A with the center line of the tenter the third stripportion 43 extends parallel to the initial strip portion 40*. The fourthstrip portion 44 of the band 3 1 overlaps the third strip portion 43 andis disposed exactly like the second strip portion 42, e.g. makes anangle B with the center line of the layer and the tenter 10'; however,the fourth portion 44 extends parallel to the second portion of 42. Theremaining portions of the layer 20 include overlapping strips 32 asdescribed with respect to the strip portions 40 through 44. Thus, layer20 comprises two groups of alternate strips where each of the groupsextends from one side of the layer 20, i.e. structure 13, to theopposite side of the layer 20 toward a third side, i.e. one end of thelayer, at different predetermined angles, i.e. angles A and 13. Everyother strip 32, e.g. strip portions 40 and 42, combine to form acontinuous overlapped disposition of adjacent mutually parallel glassstrands throughout the length of the layer 20 wherein each strandextends obliquely across its width at either an angle A or an angle B.Hence, the first layer 20 comprises a plurality of successive stripsextending in overlapping relation across the layer where the end of eachof the strips 32 at one side of the layer are positioned in lateraloifset relation in the same direction with respect to the end of each ofthe strips 32 at the opposite side.

The second station 16 provides means to dispose a second layer 50 inintimate association on the first layer 20. As shown in FIGS. 1 and 2 asuitable source such as a creel 53 located in spaced relation from thetenter 10 provides a plurality of parallel glass strands 52. From thecreel 53 the glass strands 52 travel as a band or sheet 54 of parallelstrands 52 to pass individually between guides 55 of a guide member 56and thence turn under a rotatably mounted longitudinal roll 57 extendingacross the width of the tenter 10. The longitudinal roll 57 is in closeassociation with the advancing first layer 20. As the strands 52 turnunder the longitudinal roll 57, they dispose themselves as adjacentmutually parallel normally touching strands running lengthwise of thetenter 10 and layer 50, i.e. extending parallel to the center line ofthe nonwoven structure 13.

The third strand laying station 18 provides means for traversing a bandof adjacent mutually parallel glass strands to form a third or top layer60 of the nonwoven reinforcement structure 13. In FIGS. 1 and 2 suchmeans include a carriage unit 62, which further includes a frame 63 anda carriage 64.

The frame 63 is a longitudinal box-like unit above and extendingobliguely across the width of the tenter 10. The frame 63 extends at apredetermined angle to the center line of the tenter 10 and holds thecarriage 64 in spaced relation from the tenter chains 11 and 12. As inthe case of the frame 23 the frame 63 is rotatably mounted.

As illustrated the carriage 64 includes a longitudinal support 66extending widthwise of the frame 63 and in a row a plurality ofside-by-side guide tubes 67 on the support 66. Suitable motor and drivemeans reciprocates the carriage '64 lengthwise of the frame 63. Thecarriage 64 locates the support 66 horizontally and the guide tubes 67,which open on the upper surface of the support 66, depend vertically onthe support 66 to terminate just above the plane containing the upperhorizontal paths of the chains 11 and 12.

As in the case of the first strand disposing station 14 a suitablesource such as a creel 69 provides a plurality of continuous filamentglass strands 70' to the carriage unit 62. The strands 70 advance as aband 71 from the creel 69, which is in spaced relation from the tenter10 and carriage unit 62, to travel individually through the guide tubes'67.

The speed of the reciprocating carriage 64 and the speed of theadvancing endless chains 11 and 12 (hooks 33) are proportioned todispose the band 71 as strips 72 of adjacent mutually parallel glassstrands 70 in obliquely extending and overlapping relation across thewidth of the tenter 10 as discussed in relation to the overlappingrelationship of the strips 32 comprising the bottom layer 20, except thestrips 72 extend in another direction, i.e. to the left of the centerline at the angles A and B as indicated in FIG. 5. Angles A and B agreewith angles A and B, which extend to the right of the center line inFIG. 5. The third layer 60 is in communication with the second layer 50and is separated from the first layer 20 by the second and intermediatelayer 50.

The three combined layers, i.e. layers 20, 50 and 60, advance togetherto a needling station 75, which includes a needling machine 76 having aplurality of vertically oriented needles 77 extending in a row acrossthe width of the tenter 10. The needles 77, which are normally withouthooked ends, move in and out of the multilayer structure 13 to punch aplurality of openings through the layers, such needling also somewhatseparating the filaments of the strands in the region of the openings tofurther reduce the time required for resin absorption or wet-out duringsubsequent manufacturing steps of producing a glass reinforced article.

After the needling station 75 the needled layers advance to a stitchingstation 80 comprising stitching or sewing machines 81 located across thewidth of the tenter 10 and having a plurality of sewing needles 82, eachof which provide a stitched pattern to nonadhesively join the threelayers together. Below the layers is a multi-bobbin and shuttle assembly83 working to form a two-thread lock stitch. While FIGS. 1 and 2 showthe sewing machine 81 providing a straight line stitch, a Zig-zag stitchmay also be eifectively employed. Other sewing stitches such as singleor double thread cable stitch may also be used. Moreover, one can use aknitted stitch to join the layers. The thread may be of a character thatdissolves under the influence of resins subsequently used with thestructure 13. Further, to improve the conformability of the structure ithas been useful to employ thread of unstretched thermoplastic material,e.g. thread of unstretched polyester filaments.

Suitable motor and drive means rotates a collection mandrel 85 tocollect the structure 13 into a package 86.

The apparatus includes means that trims the longitudinal edges of thestructure 13. Such means includes cooperating disc cutter 87 and arbor89 and air suction tubes 88 located at the edges of the tenter 10between the package 86 and stitching station 80. The edges of thestructure 13 pass between the disc cutters 87 and associated arbor 89 atthe zone where the chains 11 and 12 begin to reverse their direction ofmovement. As the discs 87 cut the strands of the structure 13 at itslengthwise edges, the structure 13 is freed from the hooks 33. The airsuction tubes 88 receive the scrap strand and remove it to a remotescrap collection location.

In operation the apparatus shown in FIGS. 1 and 2 produces a three layernonwoven reinforcement structure joined together without adhesives. Atthe first station 14 the apparatus advances a plurality of glass strands30 to a first advancing zone between opposite edges of the zone (thehooks 33) and traverses the strands 30 together across the zone along apath obliquely of the zones direction of movement. The speed of thezone, i.e. speed of the hooks 33, is proportional to the traversingspeed to form successive strips 32 of the strands 30 extending obliquelyin overlapping relation across the layer 20 in the form of two groups ofalternate strips with one end of each of the strips 32 in lateral offsetrelation in the direction of zone movement from the other end of each ofthe strips 32. The apparatus orients the groups of alternate strips toextend at predetermined angles A and B with the center line of the layer20 with the strands 30 extending lengthwise of the strips 32.

The apparatus of the second station 16 advances the strands 52 onto themoving first layer at a second advancing zone to form the second layerhaving the strands extending in mutually parallel usually touchingrelationship lengthwise of the tenter 10.

The apparatus of the third station 18 advances a plurality of glassstrands 70 to form the third layer on the second layer 50 at a thirdadvancing zone by traversing the strands together obliquely betweenopposite edges of the zone (the hooks 33). As in the case of the firststation 14 the traversing speed and speed of the third zone (hooks 33)are proportioned to orient the filaments 70 into successive strips 72extending obliquely in overlapping relation across the layer in the formof two groups of alternate strips with one end of each of the strips inlateral offset relation in the direction of zone movement from the otherend of each of the strips. The angles A and B of the third layer 50agree with the angles A and B of the first layer 20.

FIG. 5 shows the nonwoven structure 13 with the needle holes denoted asand stitching denoted as 91.

FIG. 6 shows a modified nonwoven structure 93 of the invention, whichcan be produced with the apparatus of FIG-S. 1 and 2 by merely removingor by-passing the guide member 56. While the bottom layer 20 and the toplayer 60 are the same as found in the nonwoven structure 13, the middlelayer is different. In lieu of the sheet 54 of adjacent mutuallyparallel strands 52 the structure 93 employs a middle layer 94, which isa fabric of parallel warp yarns and parallel woof yarns 96. The middlelayer 94 may be either woven or nonwoven. The fabric 94 runs between theroller 57, which disposes the fabric 94 in intimate association on thefirst layer 20 with its warp yarn 95 extending lengthwise of thestructure 93 of its woof yarn 96 extending across the width of thestructure 93. As the structure 13, the structure 93 is needled to haveneedle holes 90 and joined by stitching 91.

FIG. 9 illustrates yet another form of a nonwoven structure of theinvention. Shown is a three layer nonwoven reinforcement structure 102having the layer 20 as its bottom layer and the layer 60 as its toplayer. A middle layer 103 is made of strands 104 disposed in whorls orloops. Moveover, the entire structure 102 is needled to have needleopenings 90' and is joined by stitching 91.

FIGS. 7 and 8 illustrate a modified second station used with theapparatus of FIGS. 1 and 2 in place of the second station 14 to producethe second layer 103 of the nonwoven structure 102. Shown is a secondstation 100, which operates in cooperation with the first station 14 andthe third station 18 and comprises a plurality of spaced apartside-by-side strand looping devices 106 positioned widthwise of thetenter 10. Each of the strand looping devices 106 directs a strand 104in looped or whorled disposition onto the advancing bottom layer 20.

Each of the strand looping devices 106 includes an air nozzle 110 thatdirects a stream of air into the entrance end of a bent guide tube 112,and an electrical motor 114 rotates the bent tube 112 through a belt115, such rotation moving the outward end of the tube 112 through acircular path.

In operation each of the strand looping devices 106 advances a strand104 from a suitable source such as a serving package 117 onto the movinglayer 20 in a looped disposition. The strand 104 travels from theserving package 117 into the entrance end of the air nozzle 110, whichadvances the strand 104 through the bent guide tube 112. As the strand104 exists at the outlet end of the guide tube 112, the circular motionof the outlet end of the tube 112 imparts loops or whorls to strand. Aseach of the strands 104 falls onto the moving layer 20, it collects as asubstantially planar column of looped or whorled strands lengthwise onthe moving layer 20.

Each of the other strand looping devices 106 operate similarly toproduce columns of looped strands, which may somewhat overlap alongtheir lengthwise edges.

FIG. 10 shows still another modified nonwoven structure 120 according tothe invention comprising the first or bottom layer 20, a middle layer121 and the top or third layer 60. The bottom layer 20 and the top layer60 are the bottom and top layers of the nonwoven structure 13, 93 and102. The middle or second layer 121 comprises short bundles of glassfibers 122 in promiscuous disposition. While the bundles of glass fibersmay be wet, it is preferred that they be dry.

FIG. 11 shows a modified second station 123 for use with the apparatusillustrated in FIGS. 1 and 2 to produce the middle layer 121. The secondstation 123 employs strand cutting apparatus, which includes a strandsupply and strand chopping unit. The strand supply is a creel 124providing a plurality of parallel side-by-side strands 126. The strandchopping unit is a longitudinal unit extending the width of the tenter10 and includes cooperating strand advancing nip rolls 127 and 128 and alongitudinal cylindrical cutting roll 129 having radially extendingcutting blades 130. As illustrated the nip roll 128 is of largerdiameter than the nip roll 127. A motor 131 drives the cutting roll 129.The cutting blades of the roll 129 engage the larger nip roll 128, whichfunctions as a cot or cutting surface against which the blades 130 maypress. The cutting roll 129 drives the nip rolls 127 and 128 inrotation.

In operation the second station 123 cuts the strands 126 to rain shortlengths of glass fiber bundles 122 in promiscuous array onto theadvancing first layer 20. The continuous filament glass strands 126travel from the creel 124 to move between the strand advancing nip rolls127 and 128 and thence between the larger nip roll 128 and cutting roll129. As the strands 126 pass between the nip roll 128 and cutting roll129, the cutting blades 130 engage them against the surface of the niproll 128 to cut the strands 126 into the short strand lengths 122.Normally the short strand lengths 122 are in the range of from 1 inch to10 inches, 2 inches being preferred.

After the short lengths of glass strand 122 have been deposited on themoving first layer 20, the third station 18 positions the third or toplayer 60 in intimate association on the second layer 121. Moreover, asin the case of the nonwoven structures 13, 93 and 102, the nonwovenstructure 120 passes across the needling station 75 to receive needleholes 90 and immediately thereafter traverses the stitching station 80for joining the layers together by stitching 91.

FIG. 12 shows another form of the nonwoven structure of the invention,viz. a three layer nonwoven structure 135. The first or bottom layer 136includes a plurality of linear material or glass strands 137 on acarrier sheet 138 where the strands 137 extend transverse of thenonwoven structure 135. The second layer 140 includes a plurality ofmutually parallel strands 141 extending lengthwise of the structure 135.The third or top layer 142 includes looped strands 143.

FIG. 13 illustrates apparatus for making the nonwoven structure shown inFIG. 12. The apparatus includes three stations for locating linearmaterial, e.g. glass strands, in predetermined relationship on acontinuous moving belt 144, one station for each layer of the structure135. The first station 145 includes means for positioning the strands137 at a moving zone as the first or bottom layer 136 with the strands137 in adjacent mutually parallel relationship running transverse of thebelt 144. The second station 146 positions the second or middle layer ata second moving zone on the first layer 136 with the strands 141extending in closely spaced mutually parallel relationship lengthwise ofthe belt 144. The third station 147 directs the strands 1143 onto theadvancing third layer 142 in looped configuration at a third movingzone.

The first station provides means to direct the layer 136 inpredetermined relationship on the moving continuous belt 144. As shownin FIG. 11 a suitable source 148 located in spaced relation above thebelt 144 provides a plurality of mutually parallel strands (137 on thecarrier sheet 138. The carrier sheet 138 may be suitable material suchas glass web, plastic film or paper. From the creel 148 the strands 137on the carrier sheet 138 advance downwardly to turn under a rotatablymounted longitudinal roll 149 extending across the width of the belt144. The longitudinal roll 149 is in close association with theadvancing endless belt 144. As the carrier sheet .138 and strands 137turn under the longitudinal roll 149, the sheet 138 disposes the strands137 to extend widthwise of the belt 144. Other means to dispose thestrands 137 widthwise of the belt 144 Without a carrier sheet may beemployed.

The second station 146 provides means to dispose the second layer 140 inpredetermined relationship at a second zone and in intimate associationon the first layer 136. As shown in FIG. 13 a suitable source such as acreel 151 located in spaced relation above the endless belt 144 providesa plurality of parallel strands 141. From the creel 151 the strands 1411advance downwardly as a sheet of oriented parallel strands to passindividually between guides 155 of a guide member 156 and thence turnunder a rotatably mounted longitudinal roll 157 extending across thewidth of the endless belt 144. The longitudinal roll 157 is in closeassociation with the first layer 136. As the strands 141 turn under thelongitudinal roll 157, they are disposed as adjacent mutually parallelstrands running lengthwise of the endless belt 144, i.e. extendinglengthwise of the nonwoven structure 135 being produced.

The third strand laying station 147 provides means for orienting thestrands 130 at a third zone in a whorled pattern that forms the third ortop layer 142 of the nonwoven reinforcement structure 135. As in thecase of the apparatus shown in FIGS. 7 and 8, the third station 147includes a plurality of air nozzles I160 where each of the nozzles iscommunicating with the entrance end of a rotatable bent tube 162. Inoperation, each of the strands 130 travels from a serving package 167and is advanced by the air nozzle 160 into the bent tube 162. A suitablemotor 164 through a drive belt 165 rotates the bent tube 162 to whorleach of the strands 130 as described in relation to the apparatus shownin FIGS. 7 and *8. Moreover, the apparatus of the third station -147 caninclude up to three or more separate devices.

The three combined layers, i.e. layers 136, 140 and 142, advancetogether to a needling station 170, which includes a needling machine172 having a plurality of vertically oriented needles 173 extending in arow across the width of the endless belt 144. The needles 173, which arenormally without hooked ends, move into the multilayer oriented strandcomposite structure 135 to punch a plurality of openings 175, suchneedling separating the filaments of the strand in the zone of punctureand tending to open the structure 135 for faster resin absorption insubsequent manufacture of glass reinforced resin articles.

After the needling station the needled nonwoven structure 135 advancesto a stitching station 180 comprising a stitching or sewing machine 181extending across the width of the structure 135 and having a pluralityof sewing needles 182, each of which provides zig-zag stitching 184nonadhesively joining the three layers together. Below the structure 135is a multi-bobbin and shuttle assembly 183 to form a two-threaded lockstitch.

A collection mandrel 185 takes the needled and stitched togethernonwoven structure 135 from the endless belt 144 as a package 186.

FIG. 14 illustrates a four layer nonwoven structure according to theinvention. The nonwoven structure 190 has the layer 20 as its first orouter layer, the second layer 50 and the third layer 60. These layersare the layers shown in FIGS. 2 and 5 and comprise the nonwovenstructure 13. The top and outer layer of the nonwoven structure 190 isthe layer 121 including the plurality of short chopped promiscuouslydisposed chopped glass strands 122 forming a part of the nonwovenstructure shown in FIG. 10 and produced employing the apparatus shown inFIG. 11. The structure 190 has needle openings 90 and is nonadhesivelyjoined together by spaced apart stitching 91, the stitching beingdisposed sufiiciently close to hold the layer 121 together as a coherentbody.

FIG. 15 illustrates an apparatus representing a four station process ofmanufacturing the nonwoven structure 190 shown in FIG. 14. The apparatusemploys the first station 14, second station 16 and the third station 18of FIGS. 1 and 2. Station four is the apparatus of the modified secondstation 123 illustrated in FIG. 11.

At the first station 14 the apparatus advances the plurality of glassstrands 30 to a first advancing zone between the moving hooks 33 of thetenter 10 and traverses the strands 30 together across the zoneobliquely of the zones direction of movement. The speed of the zone(i.e. speed of the hooks 33) is proportional to the traversing speed toform successive the strips 32 extending obliquely in overlappingrelation across the layer 20 in the form of two groups of alternatestrips with one end of each of the strips 32 in lateral offset relationin the same direction with respect to the outer end of each of thestrips. The strands 30 extend lengthwise of the strips 32.

The apparatus of the second station 16 locates the strands 52 in amutually parallel usually touching relationship lengthwise of thestructure 13 on the moving first layer 20 at a second advancing zone toform the second layer 50.

The apparatus of the third station 18 advances a plurality of glassstrands 70 onto the second layer 50 at a third advancing zone andtraverses the strand obliquely across the zone between the moving hooks33. The traversing speed and speed of the third zone are proportioned toorient the filaments 70 into the successive strips 72 extendingobliquely in overlapping relation across the layer in the form of twogroups of alternate strips with one end of each of the strips in lateraloifset relation in the same direction with respect to the end of each ofthe strips.

The fourth station 123 cuts the strands 126 to rain short lengths ofglass fiber bundles 12 in promiscuous array onto the advancing layers.The continuous filament glass strands 126 travel from the creel 124 tomove between strand advancing nip rolls 127 and 128 and thence betweenthe nip roll 128 and cutting roll 129. As the strands 126 pass betweenthe nip roll 128 and cutting roll 129, the blades 130 engage the strandsagainst the surface of the nip roll 128 to cut them into short strandlengths 122. Normally the short strand length 122 are in the range from1 inch to 10 inches in length, 2 inches being preferred.

The four layers advance from station four to the needling station 75. Asthe layers pass across station 75 the needling machine 76 punctures theplurality of openings in the layers as discussed with relation to thenonwoven structure 13.

After the needling station 75 the layers pass or advance to thestitching station 80. Sewing machines 81 nonadhesively joins the layerstogether.

Suitable means rotates the collection mandrel 85 to wind the nonwovenstructure as a package 191.

It is apparent that, within the scope of the invention, modificationsand different arrangements may be made other than as herein disclosed.The present disclosure is merely illustrative, the inventioncomprehending all variations thereof.

I claim:

1. A nonwoven structure for reinforcing resinous material combinedtherewith comprising:

a layer including a longitudinal grouping of mutually parallelcontinuous linear elements extending lengthwise of such grouping, thelongitudinal grouping being folded into successive strips extending inoverlapping relation back and forth across the layer, the end of each ofthe strips at one side of the structure being positioned in lateraloffset relation in the same direction with respect to the other end ofeach of the strips at the opposite side of the structure, the ends ofalternate strips being in adjacent side-by-side relationship, thecontinuous linear elements of all the overlapping strips being intouching relationship; and

thread interengaging the strips effectively joining them together intoan integral structure.

2. A nonwoven structure recited in claim 1 wherein the ends of alternatestrips are in substantially side-by-side registry at the sides of thestructure.

3. A nonwoven structure recited in claim 2 where the linear elements aremultifilament textile elements.

4. A nonwoven structure for reinforcing resinous material combinedtherewith comprising:

a longitudinal layer including a longitudinal grouping of continuouslongitudinal elements folded into a plurality of successive stripsextending back and forth in overlapping relation across the width of thelayer, the strips comprising two groups of strips, of each of the groupsbeing oriented obliquely with respect to a common side to extendtherefrom each group at a different acute angle towards a common end ofthe layer, the strips of each of the groups extending generally parallelto each other in adjacent side-by-side relationship with theircontinuous longitudinal elements extending in mutually parallel relationlengthwise of such strips across the entire width thereof, thecontinuous linear elements of all the overlapping strips being intouching relationship; and

thread interengaging the strips effectively joining them together intoan integral structure.

5. A multilayer nonwoven structure for reinforcing resinous materialcombined therewith comprising:

a longitudinal layer including a longitudinal grouping of glass strandsfolded back and forth into a plurality of successive strips extending inoverlapping relation across the width of the layer, the stripscomprising two groups being oriented obliquely with respect to a commonside to extend therefrom each group at a different acute angle towards acommon end of the layer, the strips of each of the groups extendinggenerally parallel to each other in adjacent side-by-side relationshipwith their glass strands extending in adjacent mutually parallelrelation lengthwise of the strips across the entire width thereof, theglass strands of all the overlapping strips being in touchingrelationship;

another layer including a plurality of mutually parallel glass strandsextending lengthwise of the structure; and

thread interengaging the layers effectively joining them together intoan integral structure.

6. A multilayer nonwoven structure recited in claim 5 wherein the otherlayer further includes a second plurality of mutually parallel glassstrands running between the opposite sides.

7. A multilayer nonwoven structure as recited in claim 6 wherein theplurality of mutually parallel glass strands and the second plurality ofmutually parallel glass strands of the other layer are at right anglesto each other.

8. A multilayer nonwoven structure for reinforcing resinous materialcombined therewith comprising:

a longitudinal layer including a continuous group of glass strandsfolded back and forth into a plurality of successive strips extending inoverlapping relation across the width of the layer, the stripscomprising two groups of strips, the strips of each of the groups beingoriented obliquely with respect to a common side to extend therefromeach group at a different acute angle towards a common end of the layer,the

strips of each of the groups extending generally parallel to each otherin adjacent side-by-side relationship with their glass strands extendingin adjacent mutually parallel relation lengthwise of the strips acrossthe entire width thereof, the glass strands of all the overlappingstrips being in touching relationship;

another layer including a plurality of whorled glass strands; and

thread interengaging the layers effectively joining them together intoan integral structure.

9. A multilayer nonwoven structure for reinforcing resinous materialcombined therewith comprising:

a longitudinal layer including a continuous group of glass strandsfolded into a plurality of successive strips extending in overlappingrelation across the width of the layer, the strips comprising two groupsof strips, the strip in each of the groups being oriented obliquely withrespect to a common side to extend therefrom each group at a differentacute angle towards a common end of the layer, the strips of each of thegroups extending generally parallel to each other in adjacentside-by-side relationship with their glass strands extending in adjacentmutually parallel relation lengthwise of the strips across the entirewidth thereof, the glass strands of all the overlapping strips being intouching relationship;

another layer including short promiscuously disposed short glassstrands; and

thread interengaging the layers effective to join them together into anintegral structure.

10. A longitudinal multilayer nonwoven structure for reinforcingresinous material combined therewith comprising:

a first longitudinal layer including a continuous grouping of glassstrands folded into a plurality of successive strips extending inoverlapping relation across the Width of the structure, the stripscomprising two groups of strips, the strips of each of the groups beingoriented obliquely with respect to a common side to extend therefromeach group at different acute angle toward a common end of the layer,the strips of each of the groups extending generally parallel to eachother in adjacent side-by-side relationship with their glass strandsextending in adjacent mutually parallel relation lengthwise of thestrips across the entire width thereof, the glass strands of all theoverlapping strips in the first longitudinal layer being in touchingrelationship;

a second longitudinal layer in communication with the first layerincluding a plurality of mutually parallel glass strands runninglengthwise of the structure;

a third longitudinal layer in communication with the second layer andseparated from the first layer by the second layer, the third layerincluding a continuous grouping of glass strands folded into a pluralityof strips extending in overlapping relation across the width of thestructure, the strips comprising two groups of strips, the strips ofeach of the groups being oriented obliquely with respect to a sidecorresponding to the side opposite the common side of the first layer toextend from such corresponding side each group at an acute angleagreeing with the acute angle of the corresponding group in the firstlayer towards an end corresponding to an end opposite the common end,the strips of each of the groups of the third layer extending generallyparallel to each other in adjacent side-by-side relationship with theirglass strands extending in adjacent mutually parallel relationlengthwise of the strips, the glass strands of all the overlappingstrips in the second longitudinal layer being in touching relationship;and

thread interengaging the layers effectively joining them together intoan integral structure.

11. A longitudinal multilayer nonwoven structure for reinforcingresinous material combined therewith comprising:

a first longitudinal layer including a continuous grouping of glassstrands folded into a plurality of successive strips extending inoverlapping relation across the Width of the structure, the stripscomprising two groups of strips, the groups being oriented obliquelywith respect to a common side to extend therefrom each group at adifferent acute angle towards a to common end of the layer, the stripsof each of the groups extending generally parallel to each other inadjacent side-by-side relationship with their glass the common end, thestrips of each of the groups of the third layer extending generallyparallel to each other in adjacent side-by-side relationship with theirglass strands extending in generally mutually parallel relationlengthwise of the strips, the glass strands of all the overlappingstrips in the second longitudinal layer being in touching relationship;and

thread interengaging the layers effectively joining them together intoan integral structure.

13. A longitudinal multilayer nonwoven structure for reinforcingresinous material combined therewith comprising:

a first longitudinal layer including a continuous groupstrands extendingin generally mutually parallel ing of glass strands folded into aplurality of succes- Teiation lengthwise 0f the Strips, the glassStrands sive strips extending in overlapping relation across of all theOverlapping Strips in the first longitudinal the width of the structure,the strips comprising two layer being in tenehing relationship; groupsof strips, the groups being oriented obliquely a second longitudinallayer in communication with the with respect to a common side to extendtherefrom first Y including a Pinraiity ht whorled giass each group at adilferent acute angle towards a comstl'ands; mon end of the layer, thestrips of each of the groups thil'd longitudinal layer in communicationwith the extending generally parallel to each other in side-by- Seeendlayer and Separated from the first layer by side relationship with theirglass strands extending in the second layer, the third layer including acongenerally ll all l relation lengthwise of the tinuous grouping ofgiess Strands folded into a P strips, the glass strands of all theoverlapping strips rality of strips extending in overlappi g relation inthe first longitudinal layer being in touching relaacross the width ofthe structure, the strips compristionship; ing two groups of strips, thegroups being Ori second longitudinal layer in comunication with theobliquely with respect to a Side eefl'espohding t0 the first layerincluding a plurality of whorled glass side opposite the common side ofthe first layer to Strands; extend m such corresponding Side each groupat third longitudinal layer in communication with the an acute angleagreeing with the acute angle of t e second layer and separated from thefirst layer by the corresponding group in the first layer towards anSecond layer, h hi d layer i ludin a continuous end of the third layercorresponding to an end P grouping of glass strands folded into aplurality of posite the common end, the strips of each of the stripsextending in overlapping relation across the groups of the third layerextending generally Patel161 width of the structure, the stripscomprising two to each other in adjacent side-by-side relationshipgroups f Strips, the groups being i nted obliquely with their glassstrands extending in adjacent mutually with respect to a Sidecorresponding to the id Pareiie1 relation iengthwise of the Strips, theglass posite to the common side of the first layer to extend Strands of311 the Overlapping Strips in the Second from such corresponding sideeach group at an acute longitudinal layer being in touchingrelationship; and angle agreeing with the acute angle f h dthreadinterengaging the layers eifectively joining them together into anintegral structure.

12. A longitudinal multilayer nonwoven structure for reinforcingresinous material combined therewith comprising:

a first longitudinal layer including a continuous grouping group in thefirst layer towards an end of the third layer corresponding to an endopposite the common end, the strips of each of the groups of the thirdla er extending generally parallel to each other in side-bysiderelationship with their glass strands extending in generally mutuallyparallel relation lengthwise of the strips, the glass strands of all theoverlapping strips in the second longitudinal layer being in touchingrelationship;

fourth longitudinal layer and outer layer in communication with thethird layer, the fourth layer including a plurality of shortpromiscuously disposed chopped glass strands; and

threads interengaging the layers effectively joining them together intoan integral structure. 14. A nonwoven structure for reinforcing resinousmaterial combined therewith comprising:

a longitudinal layer including a continuous longitudinal grouping ofindividual mutually parallel glass strands in side-by-side relationshipwith their glass strands 5 extending in generally mutually parallelrelation lengthwise of the strips, the glass strands of all theoverlapping strips in the first longitudinal layer being in touchingrelationship;

a second longitudinal layer in communication with the first layerincluding a plurality of short promiscuously disposed chopped glassstrands;

third longitudinal layer in communication with the second layer andseparated from the first layer by the second layer, the third layerincluding a conextending in a direction lengthwise of such grouping, thecontinuous grouping being folded into successive strips extending inoverlapping relation back and forth across the width of the layer, thestrips forming a group of underlaying mutually parallel adjacent tinuousgrouping of glass strands folded into a pluslde'by'slde h and group ofovhrlappmg t rality of strips extending in overlapping relation anyparallehadiacent f Strips t Strips of across the width of the structure,the strips compristhe hndetiaylnggrohp being Oriented ohilqueiy t0 theing two groups of strips, the groups being oriented longitudinal axis ofthe layer with the same acute obliquely with respect to a sidecorresponding to the a g t a al i 0f the l yer, he trips 0f the sideopposite to the common side of the first layer to overlaying group helngOriented q y t0 the extend from such corresponding side each group atlongitudinal axis of the layer with the same acute an acute angleagreeing with the acute angle of the angle towards the end of the layer,the acute angle corresponding group in the first layer towards an endformed by the longitudinal axis and the strips of of the third layercorresponding to an end opposite the underlaying group being differentfrom the acute 15 16 angle formea by the longitudinal axis and thestrips 2,381,184 8/1945 Ripley 16159 of the overlaying group; and3,044,146 7/1962 Thomas et a1 161-50 thread interengaging the stripseffective to join them together into an integral structure. MORRISSUSSMAN, PTlmary Examlnel References Cited I 5 US. Cl. X.R.

UNITED STATES PATENTS 161 142 2,315,851 4/1943 Goldman 16159

